Metrics.md

Log pipeline metrics

Exporter send attempts (per exporter)

• otelcol_exporter_sent_log_records
• otelcol_exporter_send_failed_log_records
• Counted per send attempt; any non-nil error marks the whole batch as failed. Retries add more increments.

Queue instrumentation (when sending_queue is enabled)

• Gauges: queue size and queue capacity (in batches).
• Counters: enqueue failures for logs.
• Histograms: batch size (items) and batch size (bytes) recorded at enqueue time.

Consumed-side counters (behind feature gate)

• Item and byte counts as data leaves processors toward exporters, labeled per component/exporter.
• Requires telemetry.newPipelineTelemetry to be enabled; size counter depends on telemetry level.

Exporter helper chain

• BaseExporter composes: timeout → retry → obsreport (span + sent/failed counters) → optional queue wrapper → actual exporter.
• Counts are taken before downstream mutation so batching processors do not change the numerator.
• Spans are started per export call with attributes: exporter name and data_type=logs.

Limitations and caveats

• Attempt-based counting means retries inflate sent/failed totals; not unique record counts.
• No partial success visibility: any error marks the entire batch failed.
• Queue metrics are batch-based; histograms emit only when queueing is enabled.
• Profiles signal is not instrumented by obsreport/queue.
• Size counters rely on telemetry level/gate; if disabled you see only item counts.

What to watch

• Delivery health: otelcol_exporter_send_failed_log_records vs otelcol_exporter_sent_log_records.
• Backpressure: otelcol_exporter_queue_size vs queue_capacity; watch enqueue-failure counter for drops.
• Batch shape: otelcol_exporter_queue_batch_send_size and otelcol_exporter_queue_batch_send_size_bytes.
• Pipeline loss/refusal (with gate on): consumed item/size counters plus refusal/failure attributes from obsconsumer wrappers.